Ofwat has today confirmed household water and sewerage bills will rise by around 3.5 per cent over the next year.

Bill changes for this year will come into effect on April 1, 2013, and will apply until March 31, 2014. The impact of the new charges will vary for individual household customers depending on the company which supplies them and whether or not they have a water meter.

How much more will I have to pay?

Ofwat estimates the average household water and sewerage bill will rise by around £13. This takes into account a rate of inflation of three per cent, and will mean an average bill of £388 in 2013/14.

Customers in the South East face the biggest rise of £23 a year, while those serviced by Wessex Water will see a hike of £22.

But some will in fact pay less – South West Water customers will see their bills fall by £40. This is because household customers served by South West Water will benefit from a Government Contribution, which will reduce the bill for all households by £50 per year.

Without this reduction, which is being applied from April 2013, South West Water’s combined average bill would be increasing by two per cent, or around £10, to £549.

The bill changes for each provider are listed below:

Anglican Water: £12

Dwr Cymru Welsh Water: £7

Northumbrian Water (excluding Essex and Suffolk?): £8

Severn Trent Water: £7

South West Water: -£40

Southern Water: £23

Thames Water: £18

United Utilities: 13

Wessex Water: £22

Yorkshire Water: £12

Why is this bill increase being introduced?

Ofwat says customers’ bills are helping pay for an investment programme worth around £25 billion between 2010 and 2015. This will “allow companies to ensure customers continue to see improvements and receive a safe, reliable supply of drinking water”.

Highlights include improving 140 water treatment works and 550 sewage treatment works to maintain and improve the environment and drinking water quality; improving or replacing more than 10,000km of water mains and investing in renewable energy sources.

Regina Finn, Ofwat Chief Executive Officer, said: “These rises will help pay for investment of around £1,000 for every household in England and Wales. This will deliver real benefits - from continuing to improve the reliability of supplies to dealing with the misery of sewer flooding for thousands of customers.

“We will make sure customers get value for money, and if companies fall short in delivering their investment promises, we will take action. In the past seven years, we have made companies pay out around £550 million where they have underperformed.”